11月22日，日本滨松医科大学的一个研究小组公布，他们开发出一种可减轻副作用的抗癌剂，通过动物实验发现效果显著。
恶性肿瘤在成长到1至2厘米以上大小时，就会生长出吸收营养的“新生血管”。杉原一广准教授领导的研究小组发现，连接氨基酸的一种肽具有易于在新生血管积聚的特性。他们据此开发出与肽组合的抗癌药物，这种抗癌药物仅对新生血管起作用。
滨松医科大学与美国桑福德伯纳姆医学研究所共同开展实验，把该抗癌药物投给患有癌症的小鼠。结果发现，仅用过去用药量的四十分之一，在19天之内癌细胞消失，而小鼠完全没有出现副作用。研究小组计划对该药物进行临床试验，争取早日实现应用。
该研究成果发表于美国《国家科学院院刊》（PNAS）电子版。(生物谷Bioon.com)
doi:10.1073/pnas.1105057108
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Targeted drug delivery to tumor vasculature by a carbohydrate mimetic peptide
Hatakeyama, Shingo; Sugihara, Kazuhiro; Shibata, Toshiaki K.; Nakayama, Jun; Akama, Tomoya O.; Tamura, Naoaki; Wong, Shuk-Man; Bobkov, et al.
Although numerous carbohydrates play significant roles in mammalian cells, carbohydrate-based drug discovery has not been explored due to the technical difficulty of chemically synthesizing complex carbohydrate structures. Previously, we identified a series of carbohydrate mimetic peptides and found that a 7-mer peptide, designated I-peptide, inhibits hematogenous carbohydrate-dependent cancer cell colonization. During analysis of the endothelial surface receptor for I-peptide, we found that I-peptide bound to annexin 1 (Anxa1). Because Anxa1 is a highly specific tumor vasculature surface marker, we hypothesized that an I-peptide-like peptide could target anticancer drugs to the tumor vasculature. This study identifies IFLLWQR peptide, designated IF7, as homing to tumors. When synthetic IF7 peptide was conjugated to fluorescent Alexa 488 (A488) and injected intravenously into tumor-bearing mice, IF7-A488 targeted tumors within minutes. IF7 conjugated to the potent anticancer drug SN-38 and injected intravenously into nude mice carrying human colon HCT116 tumors efficiently suppressed tumor growth at low dosages with no apparent side effects. These results suggest that IF7 serves as an efficient drug delivery vehicle by targeting Anxa1 expressed on the surface of tumor vasculature. Given its extremely specific tumor-targeting activity, IF7 may represent a clinically relevant vehicle for anticancer drugs.
